Palo Alto Research Center, Inc. (“PARC”) has developed a filament extension atomizer system that generates aerosols from liquids. The system generally involves stretching a liquid filament between two diverging surfaces until the filament breaks up into a spray of droplets. In some versions of the system, the fluid input to the system involves doctor blades and the pressure formed between the two surfaces. In one version, the two surfaces are rollers and the rollers form a nip between them to distribute the fluid.
Typically, for most fluids this is very effective. However, for fluids with relatively high surface tension, and therefore having large contact angles on a flat and smooth surface, spreading the fluid uniformly in a controlled manner on rapidly moving surfaces becomes problematic. The spreading can typically be enhanced by using more hydrophilic materials, such as plastics with polar monomers or metal oxides, which lower the contact angle. Although even this approach often fails to generate ideal surface wetting for generating a consistent spray from high surface tension fluids.